///////////////////////////////////////////////////////////////
//  Copyright 2012 John Maddock. Distributed under the Boost
//  Software License, Version 1.0. (See accompanying file
//  LICENSE_1_0.txt or copy at https://www.boost.org/LICENSE_1_0.txt

#ifdef _MSC_VER
#define _SCL_SECURE_NO_WARNINGS
#endif

#include <nil/crypto3/multiprecision/cpp_int.hpp>
#include <boost/random/mersenne_twister.hpp>
#include <boost/random/uniform_int.hpp>
#include "test.hpp"

#if defined(HAS_GMP)
#include <nil/crypto3/multiprecision/gmp.hpp>
#endif
#if defined(HAS_MPFR)
#include <nil/crypto3/multiprecision/mpfr.hpp>
#endif
#if defined(HAS_MPFI)
#include <nil/crypto3/multiprecision/mpfi.hpp>
#endif
#ifdef HAS_TOMMATH
#include <nil/crypto3/multiprecision/tommath.hpp>
#endif
#ifdef HAS_FLOAT128
#include <nil/crypto3/multiprecision/float128.hpp>
#endif
#include <nil/crypto3/multiprecision/cpp_bin_float.hpp>
#include <nil/crypto3/multiprecision/cpp_dec_float.hpp>

using namespace nil::crypto3::multiprecision;

#ifdef BOOST_MSVC
#pragma warning(disable : 4127)
#endif

template<class T>
T generate_random() {
    //
    // Our aim is to fill up the mantissa of T with random bits,
    // the main loop simply multiplies by the largest random value
    // we produce and then adds the next random value.  It stops
    // when the next random value is too small to change the result,
    // and so "val" and "prev_val" end up with the same value.
    //
    // We start with an arbitrary value in "prev_val" - anything you
    // like as long as it's a value that our generator can not produce.
    //
    // At the end we ditch the current exponent, and replace with our own
    // randomly generated one.
    //
    typedef int e_type;
    static boost::random::mt19937 gen;
    T val = gen();
    T prev_val = -1;
    while (val != prev_val) {
        val *= (gen.max)();
        prev_val = val;
        val += gen();
    }
    e_type e;
    val = frexp(val, &e);

    static boost::random::uniform_int_distribution<e_type> ui(-20, 20);
    return ldexp(val, ui(gen));
}

template<class From, class To>
void test_convert_neg_int(From from, const boost::mpl::true_&) {
    from = -from;
    To t3(from);
    To t4 = from.template convert_to<To>();
    BOOST_CHECK_EQUAL(From(trunc(from)), From(t3));
    BOOST_CHECK_EQUAL(From(trunc(from)), From(t4));
}
template<class From, class To>
void test_convert_neg_int(From const&, const boost::mpl::false_&) {
}

template<class From, class To>
void test_convert_imp(boost::mpl::int_<number_kind_floating_point> const&,
                      boost::mpl::int_<number_kind_integer> const&) {
    for (unsigned i = 0; i < 100; ++i) {
        From from = generate_random<From>();
        To t1(from);
        To t2 = from.template convert_to<To>();
        BOOST_CHECK_EQUAL(From(trunc(from)), From(t1));
        BOOST_CHECK_EQUAL(From(trunc(from)), From(t2));
        test_convert_neg_int<From, To>(from, boost::mpl::bool_ < std::numeric_limits<From>::is_signed &&
                                                 std::numeric_limits<To>::is_signed > ());
    }
}

template<class From, class To>
void test_convert_neg_rat(From from, const boost::mpl::true_&) {
    from = -from;
    To t3(from);
    To t4 = from.template convert_to<To>();
    BOOST_CHECK_EQUAL(From(t3), from);
    BOOST_CHECK_EQUAL(From(t4), from);
}
template<class From, class To>
void test_convert_rat_int(From const&, const boost::mpl::false_&) {
}

template<class From, class To>
void test_convert_imp(boost::mpl::int_<number_kind_floating_point> const&,
                      boost::mpl::int_<number_kind_rational> const&) {
    for (unsigned i = 0; i < 100; ++i) {
        From from = generate_random<From>();
        To t1(from);
        To t2 = from.template convert_to<To>();
        BOOST_CHECK_EQUAL(From(t1), from);
        BOOST_CHECK_EQUAL(From(t2), from);
        test_convert_neg_rat<From, To>(from, boost::mpl::bool_ < std::numeric_limits<From>::is_signed &&
                                                 std::numeric_limits<To>::is_signed > ());
    }
}

template<class From, class To>
void test_convert_neg_float(From from, const boost::mpl::true_&) {
    from = -from;
    To t3(from);
    To t4 = from.template convert_to<To>();
    To answer(from.str());
    To tol = (std::max)(std::numeric_limits<To>::epsilon(), To(std::numeric_limits<From>::epsilon())) * 2;
    BOOST_CHECK_CLOSE_FRACTION(t3, answer, tol);
    BOOST_CHECK_CLOSE_FRACTION(t4, answer, tol);
}
template<class From, class To>
void test_convert_neg_float(From const&, const boost::mpl::false_&) {
}

template<class From, class To>
void test_convert_imp(boost::mpl::int_<number_kind_floating_point> const&,
                      boost::mpl::int_<number_kind_floating_point> const&) {
    for (unsigned i = 0; i < 100; ++i) {
        From from = generate_random<From>();
        To t1(from);
        To t2 = from.template convert_to<To>();
        To answer(from.str());
        To tol = (std::max)(std::numeric_limits<To>::epsilon(), To(std::numeric_limits<From>::epsilon())) * 2;
        BOOST_CHECK_CLOSE_FRACTION(t1, answer, tol);
        BOOST_CHECK_CLOSE_FRACTION(t2, answer, tol);
        test_convert_neg_float<From, To>(from, boost::mpl::bool_ < std::numeric_limits<From>::is_signed &&
                                                   std::numeric_limits<To>::is_signed > ());
    }
}

template<class From, class To>
void test_convert() {
    test_convert_imp<From, To>(typename number_category<From>::type(), typename number_category<To>::type());
}

int main() {
    test_convert<cpp_bin_float_50, cpp_int>();
    test_convert<cpp_bin_float_50, int128_t>();
    test_convert<cpp_bin_float_50, uint128_t>();
    test_convert<cpp_bin_float_quad, checked_int1024_t>();
    test_convert<cpp_bin_float_quad, checked_uint1024_t>();

    test_convert<cpp_bin_float_50, cpp_rational>();

    test_convert<cpp_bin_float_50, cpp_dec_float_50>();

#if defined(HAS_GMP)
    test_convert<cpp_bin_float_50, mpz_int>();
    test_convert<cpp_bin_float_50, mpq_rational>();
    test_convert<cpp_bin_float_50, mpf_float_50>();
#endif
#if defined(HAS_MPFR)
    test_convert<cpp_bin_float_50, mpfr_float_50>();
#endif
#if defined(HAS_MPFI)
    test_convert<cpp_bin_float_50, mpfi_float_50>();
#endif
#ifdef HAS_TOMMATH
    test_convert<cpp_bin_float_50, tom_int>();
    test_convert<cpp_bin_float_50, tom_rational>();
#endif
#ifdef HAS_FLOAT128
    test_convert<cpp_bin_float_50, float128>();
#endif
    return boost::report_errors();
}
